\begin{tikzpicture}
	\tkzDefPoints{0/0/C, 4/0/B, 0/2/A, 4/2/D}
	\tkzInterLL(A,B)(C,D)   \tkzGetPoint{O}

	\tkzDrawSegments(A,B  C,D)

	\tkzMarkAngle[size=0.4](B,O,D)  \tkzLabelAngle[pos=0.7](B,O,D){$1$}
	\tkzMarkAngle[size=0.5](D,O,A)  \tkzLabelAngle[pos=0.8](D,O,A){$2$}
	\tkzMarkAngle[size=0.4](A,O,C)  \tkzLabelAngle[pos=0.7](A,O,C){$3$}
	\tkzMarkAngle[size=0.5](C,O,B)  \tkzLabelAngle[pos=0.8](C,O,B){$4$}

	\tkzLabelPoints[below](A, B, C, D, O)
\end{tikzpicture}

